The present invention relates generally to guided munitions, and in particular to dynamic resolution imaging for terminal imaging seekers.
Modern precision guided munitions require the use of terminal imaging seekers to improve weapon effectiveness. Seekers often reside in the nosecone of the munition and thus, weight and volume are important considerations. Seekers which use autonomous target acquisition and recognition algorithms must provide high resolution images at long ranges, which requires the use of a high pixel count focal plane array (FPA) in order to discern fine details regarding potential targets and distinguish those fine details from background clutter.
A desired resolution for a seeker is referred to as the number of pixels-on-target. To increase the pixels-on-target, the field-of-view may be narrowed, but this reduces the search area of the seeker, which risks missing the target completely. A larger FPA generally requires larger optics, which utilizes more volume within the munition. Additionally, with a larger FPA, as the munition approaches the target, the number of pixels-on-target becomes unnecessarily large, which slows the automatic tracking algorithms for the target.
During the final stages of engagement, it is desirable to increase the target tracking update rate (i.e., frames per second). The update rate, however, is limited by the high pixel count coming into the target tracking algorithm. To increase the update rate, adjacent pixels may be ‘binned’ to reduce the total pixel count. However, this method does not reduce the packaging size of the seeker, as it does not reduce the size of the FPA. It is desirable to reduce the volume and weight of the seeker without narrowing the field-of-view and while retaining the desired pixels-on-target.